This invention relates generally to cellular cushions, and more particularly, to methods for fabricating cellular cushions.
Individuals confined to wheelchairs, for example, may develop tissue breakdown and/or pressure sores, which may be extremely dangerous and difficult to cure. More specifically, because such individuals may primarily remain in a seated position for extended periods of time, their weight may be concentrated in the bonier portions of the individual's buttocks. Over time, blood flow to such areas may decrease, causing tissue to break down in these areas.
To facilitate reducing the weight concentration of such individuals, at least some known wheelchairs use cellular cushions to facilitate distributing the individual's weight over a larger area and across the individual's buttocks, and to facilitate decreasing the user's weight concentration in smaller areas. Known cellular cushions include a plurality of hollow fluid-filled cells which project upwardly from a common base. The plurality of air-filled cells are coupled in flow communication through the base, such that the air pressure within the cells is at the same pressure throughout the plurality of cells, and as such, each cell exerts the same pressure against an individual's buttocks.
To facilitate providing uniform load supporting characteristics, known cushions are fabricated with a plurality of substantially identical cells. More specifically, to facilitate preventing pressure sores to a seated user, known cushion cells are fabricated using a dipping process in which the cells may be formed over a mandrel. During a dipping process the cells are formed by repeatedly dipping a form into a vat of liquefied material, such as natural or synthetic latex. The dipping process may be repeated until the material on the form reaches a desired thickness, wherein the accumulated material is cured and stripped from the mold. However, depending on the shape and number of the cells being formed, such cushions may be difficult and/or expensive to manufacture. Specifically, the external profile of at least some known cells may prevent the cushion material from being distributed uniformly across the cushion. Moreover, depending on the shape of the cells, air bubbles or pockets may develop within the cell sidewalls during the dipping process. Over time, because the air bubbles weaken the structural integrity of the wall in which they are formed, such bubbles may eventually lead to cushion failure.